Yoga term: Hanumanasana (pose of the Monkey God Hanuman)
This is a good stretch to do in between the T-Square and Praising the Moon. Feel free to go full Hanuman. For that just reach the rear leg straight back and keep the hips squared to the front of the room and rolled slightly forward. Then with palms together look and reach straight up, as if extending a prayer to the heavens. The example above is not absolutely necessary in the Foundational sequence I outline. It is a good opportunity to get a more intense stretch to the area of the hamstring just below the butt to the knee which can get neglected with forward bends.
Hips squared to the front of the room. One leg straight forward from the hip, toes up. Keep relaxed as possible. rear leg at a 90 degree angle. Bend at the hip keeping the back as straight as possible. Some caving in of the chest may be necessary for those with very tight hamstrings. This is ok, the focus of the stretch is on the hamstring and not so much form. Form can come later.